## Trivial Beturing program that swaps a's and b's along a line.
## $Id$
# D(40, 4)
# @(40, 4)
$bbab$
# C(0, 0)
# @(0, 0)
 . . . . . .
*v*<*<*<*>*v
aa .ab . .aa .
>/*>./*^*^</*v
bb .ba . .bb .
>/*^./*^*^</*v
$$ .$$ . .$$ .
>/*^</*>*^.@*v
         . . .
*@      *^*<*<
